With an increase in communication demand, an improvement in throughput is requested for packet switching apparatuses, such as a layer 2 switch, which transfers packets, and the like. In order to improve the throughput, packets are processed separately by a plurality of flows depending on priority, destination, and the like. Accordingly, management mechanisms of buffers for storing packets have become complicated.
For example, a chain management method, in which buffers for storing packets are managed by a series of pointer chains linked by link pointers, is known. By the chain management method, a pointer of an address at which a packet is written is obtained from a pointer chain, and after a packet is read from the buffer, the pointer is returned to the pointer chain.
As for the chain management method, for example, Patent Document 1 has disclosed a point where when a broken link occurs in an empty buffer chain for a certain buffer group, the buffer group is excluded from a buffer acquisition target, and the empty buffer chain is reorganized after passage of a certain time period. Also, Patent Document 2 has disclosed a point of automatically restoring a link at the time of obtaining and releasing a single pointer-type buffer in/from a single pointer-type buffer pool. As related-art technical documents, Japanese Laid-open Patent Publication Nos. 2000-285011 and 10-254763 have been disclosed.